Pneumatic dooe check



(No Model.) 3 Sheets-Sheet 1. G. 0. CASE. PNEUMATIG DOOR CHECK.

No. 475,930. Patented May 31, 1892.-

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' PNEUMATIC DOOR GHEGK.

No. 475,930. Patented May 31, 1892.

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(No Model.) 3 Sheets-Sheet 3 O. 0. CASE. PNEUMATIC DOOR OHEGK.

No. 475,930. Patented May 31, 1892.

1447/7552; Man/2m MW WW4 I 6M NITED STATES PATENT OFFICE.

OROMW'ELL 0. CASE, OF NEW BRITAIN, CONNECTICUT, ASSIGNOR TO THE P. do

F. CORBIN, OF SAME PLACE.

PNEUMATIC DOOR-CHECK.

SPECIFICATION forming part of Letters Patent No. 47 5,930, dated May 31, 1892.

Application filed January 25, 1892. Serial No. 419,109. (No model.)

To all whom it may concern; opened and closed, and I connect said cross- Be it known that I, OROMWELL 0. CASE, a head with the respective cylinder-heads by citizen of the United States, residing at New means of the links or pitmen 14, the same be" Britain, in the county of Hartford and State ing pivoted to said cross-head or disk on dia- 5 of Connecticut, have invented certain new and metrically-opposite sides. The cylinder end useful Improvements in Pneumatic Door- 11 is fitted tightly to the inner cylinder and Checks, of which the following; is a specificais provided with a tapering hole for a valvetion. seat. WVithin this hole is a valve 15, having My invention relates to improvements in valve-stem16,thatextends through the screw- 60 [o pneumatic or fluid door-checks; and the chief sleeve 17 in the head of the inner cylinder. object of my improvements is general effi- This valve-rod is provided with a collar-like ciency of the article. projection 18, Fig. 1, one side of which forms In the accompanying drawings, Figure 1 is a shoulder for contact with the inner end of a front elevation of my cheek and so much of the adjusting-screw sleeve 17, while the outer 65 :5 a door-closing device as to show its connecside forms a shoulder to furnish a seat on the tion therewith. Fig. 2 is a side elevation of valve-rod for one end of the spring 19, the the same. Fig. 3 is a plan view of my check opposite end of which spring rests upon the with the door-closing spring and its case recylinder end11. 'lheinner cylinder is grooved moved. Fig. Aisalongitudinal section mainly at one or more points, as at. 20, for the recep- 70 no on the line 00 0c of Fig. 3, but with the parts in tion of any suitable packing to practically a different position. Fig. 5 is a correspondconvert that end of the inner cylinder, in coning section with the parts in the position repnection with its end 11, into a piston, while resented in Figs. 1 to 4, together with 'a valvethe body of the cylinder serves as the pistonreleasing lever; and Fig. 6 is a longitudinal rod. One or more perforations 21 are made 75 section of my check as adapted more espethrough the head 10 of the inner cylinder for cially for liquid instead of air. the free passage of air. Then the door is A designates a spring box or case bearin g closed, the parts are in the position shown in a vertical shaft B, Figs. 3 and 4, on the upper Figs. 1, 2, 3, and 5. Upon opening the door end of which shaft a lever-arm O is secured. the shaft B is moved to carry the cross-head 80 0 The spring-box is provided with perforated 13 in the direction indicated by the dart in wings 7, by means of which it is secured to a Fig. 3, whereby said eross-head and connected door or its j amb, while the lever-arm G is conlinks act to force the cylinders apart, while nected by a pivoted link and bracket to the they are supported in position by the socket jamb of the door in any ordinary manner of 9, carrying them from the position illustrated 8 5 connecting such springs. I have shown only in Fig. 3 into that shown in Fig. 4. As the one part 8 of such link, inasmuch as the parts cylinders thus move, the valve 15 opens autothus far specifically described are old and not matically to let the air pass freely into the of my invention, and any vertical shaft, concompressing-chamber formed in the outer cylnectin g devices, and door-closing spring may inder. hen the shaft moves back again in 90 be substituted for these parts. closing the door and the cylinders return to I secure my door-check bracket D to the their normal position,the valve is again closed under side of the spring-box A, said bracket to form an air-cushion and check the force of being provided with a cylindrical socket 9. the door. The air is rapidly compressed to \Vithin said socket I mount the outer cylinform a cushion or check by the movement of 5 der E, and within said outer cylinder is the both cylinders, which in effect act like the inner cylinder F, having head 10 and end 11. simultaneous movement of cylinder and its The outer cylinder is also provided with a piston to contract both ends of the cushioninghead 12. A cross-head 13 (or, if preferred, a chamber at the same time. By turning the disk) is connected in any proper manner with screw-sleeve 17 so that the collar-like projec- 10c the vertical shaft B within the bracket D, so tion 18 bears upon its end when the valve as to oscillate with said shaft as the door is comes to its seat and is closed for its work.

the valve may be so set that it will leak more or less, and thereby regulate the wasting away of the air-cushion to permit the final closing or last stroke of the door to be as slow or rapid as may be desired. The distance that the valve will be held from its seat when so adjusted is too small to admit of being shown in the drawings.

Fig. 5 shows the parts with the shaft, crosshead, and links removed. On the inside of the head 10 of the inner cylinder I pivot alever 22, with one end extending through slots in the cylinders and its other end entering a A groove in the collar-like projection 18. Just before the parts reach the position shown in said figure as the door is being closed the end wall of the slot in the outer cylinder strikes the lever 22, so as to move the valve-stem a little and open the valve against the force of the spring, and thereby wholly release all the air in the compression-chamber and permit the spring to act on the door with all its force.

In Fig. 6 I have shown my cylinder as arranged for a liquidas, for instance, glycerine or oil. These cylinders will be supported in a cylindrical socket and operated by a shaft, cross-head, and links, as before described. The inner cylinder is provided with an end 22, having a filling-plug 23 and stuffing-box 24, through which the hollow pistonrod 25 extends. Said piston-rod is screwed into the head 12 of the outer cylinder, so as to be rigid therewith, while a piston 26 is secured to its opposite end. This piston, instead of having a central valve for the rapid passage of the liquid, has one or more valves 27 at a point or points outside of the center, the valves being of an ordinary construction. At a point near the junction of the hollow piston there is a leakage-hole 28, and inside of said hollow rod is the screw-adjustable leakage valve-rod 29, with its end reaching said hole, whereby by screwing said valve-rod out or in, more or less of said hole 28 may be covered or uncovered to make the leakage greater or less, as may be desired. In this construction the outer cylinder, its head 12, the piston-rod, and piston all move together as one piece, while the inner cylinder moves in the opposite direction. \Nhen the cylinders are moving outwardly, as in opening the door, the liquid flows freely through the valves 27 from the chamber in the back of the piston to the chamber at its front. On the reverse movement of the cylinders in closing the door the valves 27 are closed and the liquid can only pass through the leakage-hole 28, thereby checking the closing of the door to a greater or less extent, according to the adjustment of the valve-rod 29.

In the arrangement of the cylinder as first described, and also in Fig. 6, both ends of the fluid-compressing chamber have a synchronical movement from and toward each other, thereby more rapidly contracting said chamber than in prior constructions, in which one end only moves, while the other end is stationary. In both arrangements I employ an outer and inner cylinder and mechanism for moving them simultaneously in opposite directions.

In the construction first described I combine the passage-valve with an adjustable and forming a com pression-chamber, with opcrating devices for moving said cylinder and its piston simultaneously in opposite directions, and carrying both ends of said compression-chamber toward each other, substantially as described,and for the purpose specified.

2. In a door-check, the combination of an outer and inner cylinder-,both movably mounted and fitted one within the other, and operating devices for simultaneously moving both of said cylinders in opposite directions, substantially as described, and for the purpose specified.

3. In a door-check, the combination of an oscillating or vibratory shaft, a cross-head moving therewith, a cylinder and piston, and a pair of links connecting said cylinder and piston with said cross-head for moving simultaneously in opposite directions, substantially as described,and for the purpose specified.

4:. In a door-check, the combination of a cylinder and piston, the latter having a valveseat, the valve 15, valve-stem 16, having a shoulder, and the adjustable screw-sleeve 17, mounted in a fixed position with reference to said valve-seat, whereby the leakage of the valve when closed for work may be regulated, substantially as described.

5. In a door-check, the combination of a holding-bracket having a cylindrical socket 9, a cylinder E, fitted to move within and supported by said socket, a piston fitted within and supported by said cylinder, and mechananism for moving said cylinder and piston within said socket, substantially as described, and for the purpose specified.

6. In adoor-check, the combination of an outer and inner cylinder, the latter forming a piston and having a valve-seat, the valve 15, valve-stem 16, the head 10 of said. inner cylinder, operating mechanism for moving said cylinders, and the release-lever 22, having one end arranged for engagement with said outer cylinder and its opposite end engaged with said valve-stem, substantially as described, and for the purpose specified.

CROMWELL 0. CASE. WVitnesses:

ALBERT N. ABBE, CHAS. E. WETMoRE. 

